Recall performance, plasma cortisol and plasma norepinephrine in normal human subjects

Area of Science:

• Neuroendocrinology
• Cognitive Neuroscience
• Psychophysiology

Background:

• The hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) are key neuroendocrine systems involved in stress response and cognitive function.
• Understanding the relationship between these systems and memory performance is crucial for cognitive health research.

Purpose of the Study:

• To investigate the correlation between HPA-axis (cortisol) and SNS (norepinephrine) activity and recall performance in healthy adults.
• To differentiate the roles of morning and afternoon neuroendocrine activity in effortful versus automatic memory processing.

Main Methods:

• Twenty-two healthy subjects performed a short-term word list recall task.
• Plasma cortisol (CORT) and norepinephrine (NE) levels were measured via venipuncture.
• Pearson correlation and stepwise multiple regression analyses were used to assess relationships between hormone levels and memory processing measures.

Main Results:

• Plasma CORT showed a positive correlation, and plasma NE showed a negative correlation with effortful processing measures.
• Stepwise regression indicated that morning plasma CORT positively influences effortful processing.
• Afternoon plasma NE negatively influences effortful processing.

Conclusions:

• Morning HPA-axis activity, indicated by cortisol, appears to enhance effortful cognitive processing.
• Afternoon SNS activity, indicated by norepinephrine, may inhibit effortful cognitive processing.
• These findings suggest distinct temporal roles for the HPA axis and SNS in modulating human memory performance.